Improvement in dies and shoes for quartz-mills



S. BARTOL 8 J- H. LEUZARDER.

nms AND SHOES FOR QUARTZ-MILLS. No. 183,362.

Patented Oc.t.1'7. 1876.

STATES PATENT OFFIC' SAMUEL F. BABTOL AND JULES M. LEUZARDER, OF BOSTON,MASS.

-lMPROVEMENT IN DIES AND SHOES FOR QUARTZ-MILLS.

Specification forming part of Letters Patent No. 183,362, dated October17, 1876; application filed October 2, 1876. v

To all whom it may concern.-

Be it known that we, SAMUEL F. BARTOL and Jones M. LEUZARDER, of Boston,in the county of Sufl'olk and State of Massachusetts, have invented anew and useful Improvement in Dies and Shoes for Quartz-Mills; and we dohereby declare the following to be a full, clear, and exact descriptionof the same, reference being had to the accompanying drawings formingpart of this specification.

Our invention relates to mills for crushing quartz; and consists inimproved dies and shoes for the same, the peculiar nature of whichimprovement will be fully and clearly set forth hereinafter.

It is well known that the dies and shoes in quartzmills are subject tosuch jarring and crushing action, by reason of the heavy blows necessaryto crush the stone placed between them, that they require to be made ofmaterial possessing in one combination the greatest possible hardnessand tenacity. This is necessary in order to have unyielding surfaceswithout that liability to fracture inherent in most hard substances.

Hitherto these dies and shoes have been made either of cast-iron withchilled surfaces or of steelchicfly of the chilled cast-iron. Theaverage life of those made of cast-iron with the chilled surfaces, byreason of great jar and wear when in action, is .about thirty days; but,as the places Where the dies and shoes are used are remote fromrailroads, and from the foundries where such articles are cast, theexpense of transportation often forms the largest element of their cost,and the articles, when worn out at the mines, are useless and valuelessfor any purpose; nor has the evil been remedied by a substitution ofcast-steel, the greater durability of the steel dies and shoes notpaying the greater cost of v the material.

A better and cheaper material for this special purpose we have found inthe bug or shot iron, which is obtained from the ashes or cinders thatcome from a cupola-furnace. This material, as we have found byexperiment, may be readily cast into the proper shapes, and the dies andshoes so made possess the combined qualities of hardness and durabilityin a greater degree than the caststeel, while, by reason of the factthat the material has heretofore been considered almost worthless,except for the purpose of weights, the improved dies and shoes of thismaterial can be made cheaper than the cast-iron.

The material may be separated from the foreign matters with which it ismixed by processes now known, and may be cast into the shapes requiredby the ordinary methods of casting. The extreme hardness and tenacityare inherent in the iron itself, and there is no need of furtherhardening, and, as the articles are fit for use when taken from themold, this inherent hardness is not objectionable, as in articles whichneed finishing after casting. The hardness and tenacity of this materialare uniform through the whole mass, it difieriug in this respect fromchilled iroii, in which the hardness is greatest at the surface anddiminishes below it.

The material used in our improved dies and shoes appears to derive thequalities which render it valuable for this purpose from the cooling andchilling which it receives while in a finely-divided condition.

The iron may be intentionally madeby a similar process for the expresspurpose, and have the same qualities; but ordinarily the waste iron isabundant and cheaper.

In the drawings, the shoe is represented at A, with a shank, a, for theattachment of the boss. The die is represented at B, and may, as usual,be round or square, and fixed in place in any of the well known ways.

The lifting apparatus, being of ordinary construction, need not bedescribed here.

These shoes can also be applied to amalgamating-pans.

We claim as our invention- A shoe and corresponding die (one or both)for quartz-crushing mills and amalgamatingpans, composed of the waste orbug iron from the ashes from a cupola-furnace, or from similar source,as set forth.

SAMUEL F. BARTOL. JULES M. LEUZARDER. Witnesses:

EDWARD P. LITTLE, GEo. F. BARTOL.

